According to the story of Artur-san who was accompanying me, the fact that ancient dragons existed was something serious. As it usually lived within a domain of monsters humans didn’t venture into, there virtually was no one who had seen its appearance.
I was told that they possess a life span of tens of thousand years. Actually dying of old age and after death turning into an undead, no one had been aware of this fact.
“Then, how were you able to confirm that the bone dragon was actually an ancient dragon?” (Wendelin)